This invention relates to spherical motors and, in particular, to the utilization of such motors in robotics. Spherical motors are known in the prior art and, in particular, attention is called to the following U.S. patents:
Laing et al. U.S. Pat. No. 4,352,646, Oct. 5, 1982 PA1 Bers, U.S. Pat. No. 3,178,600, Apr. 13, 1965 PA1 Bers, U.S. Pat. No. 3,052,859, Sept. 4, 1962.
The two Bers patents are divisional applications of a common application Ser. No. 004,370 filed Jan. 25, 1960, and thus are identical in disclosure. Reference is therefore had to the earlier of these patents. The teaching is with respect to resolver type function generators and is thus not directly related to spherical motors. However, a stator with winding 10 is disclosed in surrounding relation to the hollow spherical member 16 also having a winding 12. Because the current density has a sinusoidal distribution along the inner surface of the outer member 14 or stator, angular rotation of the member 16 about its supporting shaft 36 (see FIG. 4) causes a sinusoidal variation in the flux produced by the winding 10 as coupled to the winding 12. Thus, angular rotation of a machine element imparted to the shaft 36 allows accurate resolution of this angular movement.
The Laing et al. patent is directed to a spherical motor for driving the impeller of a pump. The history and background of such motors, as discussed in this patent, is indicative that such motors normally impart rotation to the rotor thereof about a single axis (horizontal in the case of the patent.)
In addition to the above patents, applicants are aware of the following publications:
F. Williams, E. Laithwaite, and L. Piggot, BRUSHLESS VARIABLE-SPEED INDUCTION MOTORS, Proc. IEE, Vol. 104A, No. 2097U, pp 102-122, June 1956.
F. Williams, E. Laithwaite, and G. F. Eastham, DEVELOPMENT AND DESIGN OF SPHERICAL INDUCTION MOTORS, Proc. IEE, Vol. 106A, No. 3036U, pp 471-484, December 1959.
E. Laithwaite, DESIGN OF SPHERICAL MOTORS, Electrical Times, vol. 9, pp 921-925, June 1960.
A. Lebedev and P. Shinayev, MOMENTS ACTING IN A SPHERICAL MOTOR IN A MAGNETIC SUSPENSION, Priborostroegie, vol. 16, No. 5, pp 85-88, 1973.
A. Rozovskii and L. B. Svnolobova, ELECTROMAGNETIC PROCESSES IN AN ASYNCHRONOUS MOTOR WITH A SPHERICAL HOLLOW ROTOR, Electromekh, N.11, p 1231-1239, November 1976.
The above publications provide background information on spherical motors but are not believed to be germane to the subject matter disclosed and claimed herein.